A cold sore is an infection which is caused by the herpes virus. A cold sore is an inflamed spot on or near the lips, with one or more blisters. Cold sores may itch or burn. After a few days, the blisters dry up and scab over. This means the skin under the scab is starting to heal.
Once infected with the herpes virus, it stays in your body forever. Cold sores are passed on through skin-to-skin such as hugging and kissing. The virus typically reappears and can cause an outbreak when people have a lowered immune system, are stressed or exposed to too much sunlight. Cold sores are also common around the time of menstrual periods. If you have a cold sore, you are contagious. Touching the blisters with your fingers may cause the virus to spread.
If you have a cold sore you should avoid touching it. It also helps to protect your lips from exposure to bright sunlight. In addition, there are a number of products that can help prevent or treat cold sores. See below for more information.